package Easy.q2;

public class q2p1 {
    /*
* 给你两个 非空 的链表，表示两个非负的整数。
* 它们每位数字都是按照 逆序 的方式存储的，并且每个节点只能存储 一位 数字。
请你将两个数相加，并以相同形式返回一个表示和的链表。
你可以假设除了数字 0 之外，这两个数都不会以 0 开头。
来源：力扣（LeetCode）
链接：https://leetcode-cn.com/problems/add-two-numbers
著作权归领扣网络所有。商业转载请联系官方授权，非商业转载请注明出处。*/

    /**
     * Definition for singly-linked list.
     * public class ListNode {
     * int val;
     * ListNode next;
     * ListNode() {}
     * ListNode(int val) { this.val = val; }
     * ListNode(int val, ListNode next) { this.val = val; this.next = next; }
     * }
     */
    public ListNode addTwoNumbers(ListNode l1, ListNode l2) {
        ListNode temp = new ListNode();
        ListNode listNode = temp;
        int higher = 0;
        while (l1 != null && l2 != null) {
            int a = l1.val;
            int b = l2.val;
            temp.next = new ListNode();
            temp = temp.next;
            temp.val = (a + b + higher) % 10;
            higher = (a + b + higher) / 10;
            temp.next = new ListNode();
            l1 = l1.next;
            l2 = l2.next;
        }

        while (l1 != null || l2 != null) {
            int a = l1 == null ? 0 : l1.val;
            int b = l2 == null ? 0 : l2.val;
            temp.next = new ListNode();
            temp = temp.next;
            temp.val = (a + b + higher) % 10;
            higher = (a + b + higher) / 10;
            temp.next = new ListNode();
            temp = temp.next;
            if (l1 == null) {
                l2 = l2.next;
            } else {
                l1 = l1.next;
            }

        }

        if (higher != 0) {
            temp.next = new ListNode();
            temp = temp.next;
            temp.val = higher;
        }

        listNode = listNode.next;
        return listNode;
    }
}
